Characterization of a Novel Species of <i>Legionella</i> Isolated from a Healthcare Facility: <i>Legionella resiliens</i> sp. nov
Sandra Cristino,
Maria Rosaria Pascale,
Federica Marino,
Carlo Derelitto,
Silvano Salaris,
Massimiliano Orsini,
Stefano Squarzoni,
Antonella Grottola,
Luna Girolamini
Affiliations
Sandra Cristino
Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
Maria Rosaria Pascale
Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
Federica Marino
Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
Carlo Derelitto
Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
Silvano Salaris
Unit of Biostatistics, Epidemiology and Public Health, Department of Cardiac, Thoracic, Vascular Sciences, and Public Health, University of Padova, Via Loredan, 18, 35121 Padova, Italy
Massimiliano Orsini
Laboratory of Microbial Ecology and Genomics of Microorganisms, Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro, Italy
Stefano Squarzoni
Unit of Bologna, CNR Institute of Molecular Genetics “Luigi Luca Cavalli-Sforza”, 40136 Bologna, Italy
Antonella Grottola
European Society of Clinical Microbiology and Infectious Diseases (ESCMID), Study Group for <i>Legionella</i> Infections (ESGLI), 4001 Basel, Switzerland
Luna Girolamini
Department of Biological, Geological, and Environmental Sciences, University of Bologna, Via San Giacomo 12, 40126 Bologna, Italy
Two Legionella-like isolates, 8cVS16T and 9fVS26, were isolated from a water distribution system (WDS) in a healthcare facility. Cells were Gram- and Ziehl Neelsen-stain-negative, rod-shaped, motile, and exhibited a blue-white fluorescence under Wood’s lamp at 365 nm. The strains grew in a range of 32–37 °C on BCYE with L-cysteine (Cys+), GVPC, and MWY agar medium, with a positive reaction for oxidase, catalase, and gelatinase. The dominant fatty acids were summed features 3 (C16:1ω7c/C16:1ω6c) (27.7%), C16:0 iso (17.5%), and C16:0 (16.3%), and Q13 as the major ubiquinone. The mip and rpoB gene sequences showed a similarity of 96.7% and 92.4%, with L. anisa (ATCC 35292T). The whole genomes sequencing (WGS) performed displayed a GC content of 38.21 mol% for both. The digital DNA-DNA hybridization (dDDH) analysis demonstrated the separation of the two strains from the phylogenetically most related L. anisa (ATCC 35292T), with ≤43% DNA-DNA relatedness. The Average Nucleotide Identity (ANI) between the two strains and L. anisa (ATCC 35292T) was 90.74%, confirming that the two isolates represent a novel species of the genus Legionella. The name proposed for this species is Legionella resiliens sp. nov., with 8cVS16T (=DSM 114356T = CCUG 76627T) as the type strain.
